Download Chapter 10 (Lesson 1,2,3) Test Study Guide

Chapter 10 (Lesson 1,2,3) Test Study Guide-7th Grade Science
*Complete this study guide using pencil.
1.A _____________________________is a “factor” that controls a trait.
2.An______________________________is a different form of a gene.
3.A ___________________________organism is an offspring that is the result of many generations that
have the same form of a trait. An organism that has the same alleles passed through many generations.
4.A ____________________________organism has two different alleles for a trait.
5.A__________________________allele is one whose trait always shows up in the organism; “stronger”
6.A ___________________________allele is one that is hidden or masked; “weaker”
7._____________________________is the study of heredity.
8._______________________________is the passing of genetic traits from parent to offspring.
9.A chart that describes all the ways alleles can combine in a genetic cross is called a(n)
__________________________________.
10.An organism’s ______________________________refers to its physical appearance or visible traits.
11.An organism’s ______________________________refers to its genetic make-up or the alleles it has.
12.What is an organism called for having two identical alleles for a trait? __________________________
13.What is an organism called for having two different alleles for a trait?__________________________
14.What is fertilization? _________________________________________________________________
15.What is probability? _________________________________________________________________
Match the following inheritance patterns with their description.
a.incomplete dominance
b.codominance
c.multiple alleles
d. polygenic inheritance
16_______ three or more alleles determine the trait
17_______one allele is only partially dominant; the heterozygote (hybrid) will have a blended appearance
18.________more than one gene affects the trait
19.________both alleles of a gene are expressed equally; both alleles will be present in the heterozygote
TRUE/FALSE
20_____________Environmental factors can influence the way genes are expressed.
21_____________Most traits are the result of simple dominance inheritance patterns.
Use the key to identify whether the following traits are influenced by the inheritance, the environment, or
both.
I=inheritance
E=environment
B=both inheritance and environment
22________the ability to cough
23________dyed hair color
25________the ability to sing well
26________the ability to run
27________being able to play a sport well
24________natural skin color
SHORT ANSWER
28.In all of Mendel’s genetic crosses with pea plants, what proportion did he find the “lost” form of the
trait reappear in the F2 generation? Choices: (1/4, 1/2, 3/4, all) ________________________________
29.What is the probability of producing a tall pea plant from a genetic cross between two hybrid tall pea
plants? (perform the Punnett Square to solve)_______________________________
30.A purebred chicken with white feathers is crossed with a purebred chicken that has black feathers.
Each of their offspring has both black and white feathers. What inheritance pattern can explain the
offspring’s traits?_________________________________
31.If a homozygous dominant black guinea pig is crossed with a homozygous recessive white guinea pig,
what is the probability that an offspring will have black fur? (perform the Punnett Square to solve)
_________________________________
32a).A blue frog is crossed with a yellow frog. All the offspring are green. What inheritance pattern can
explain the blended appearance of the hybrid offspring?_______________________________________
32b) If two green frogs are crossed, what is the probability their offspring will be blue? green? yellow?
(perform a Punnett Square to solve) blue:_________green:_________yellow:___________
Use the Punnett Squares above to answer the questions below.
33.Which trait—white flowers or purple flowers—is controlled by a dominant allele? ________________
34.In which generation (F1 or F2) are the parents hybrids? ______________________________
35.In the F1 generation, what is the genotype of the offspring?_________________________
36.In the F2 generation, what percent of the offspring have purple flowers? ______________________
Study Guide Answers
1.A gene is a “factor” that controls a trait.
2.An allele is a different form of a gene.
3.A purebred organism is an offspring that is the result of many generations that have the same form of a
trait. An organism that has the same alleles passed through many generations.
4.A hybridorganism has two different alleles for a trait.
5.Adominant allele is one whose trait always shows up in the organism; “stronger”
6.A recessive allele is one that is hidden or masked; “weaker”
7.Genetics is the study of heredity.
8.Heredity is the passing of genetic traits from parent to offspring.
9.A chart that describes all the ways alleles can combine in a genetic cross is called a Punnett Square.
10.An organism’s phenotype refers to its physical appearance or visible traits.
11.An organism’s genotype refers to its genetic make-up or the alleles it has.
12.What is an organism called for having two identical alleles for a trait? Homozygous (HH or hh)
13.What is an organism called for having two different alleles for a trait?Heterozygous (Hh)
14.What is fertilization? The union of a sperm cell and an egg cell.
15.What is probability? The likelihood that an event will happen.
Match the following inheritance patterns with their description.
a.incomplete dominance
b.codominance
c.multiple alleles
d. polygenic inheritance
16___C____ three or more alleles determine the trait
17___A___one allele is only partially dominant; the heterozygote (hybrid) will have a blended
appearance
18.___D____more than one gene affects the trait
19.___B____both alleles of a gene are expressed equally; both alleles will be present in the heterozygote
TRUE/FALSE
20__TRUE_____Environmental factors can influence the way genes are expressed.
21__FALSE____Most traits are the result of *simple dominance inheritance patterns. COMPLEX
Use the key to identify whether the following traits are influenced by the inheritance, the environment, or
both.
I=inheritance
E=environment
B=both inheritance and environment
22___I____the ability to cough
23___E____dyed hair color
25___B____the ability to sing well
26___I____the ability to run
27___B____being able to play a sport well
24___I____natural skin color
SHORT ANSWER
28.In all of Mendel’s genetic crosses with pea plants, what proportion did he find the “lost” form of the
trait reappear in the F2 generation? Choices: (1/4, 1/2, 3/4, all) _________one-fourth_______________
29.What is the probability of producing a tall pea plant from a genetic cross between two hybrid tall pea
plants? (perform the Punnett Square to solve)____________75%______________
T
T
t
t
TT
Tt
Tt
tt
(TT and Tt will be tall; tt will be short)
30.A purebred chicken with white feathers is crossed with a purebred chicken that has black feathers.
Each of their offspring has both black and white feathers. What inheritance pattern can explain the
offspring’s traits?_____codominance___________
31.If a homozygous dominant black guinea pig is crossed with a homozygous recessive white guinea pig,
what is the probability that an offspring will have black fur? (perform the Punnett Square to solve)
____________100%________________
B
B
b
Bb
Bb
b
Bb
Bb
32a).A blue frog is crossed with a yellow frog. All the offspring are green. What inheritance pattern can
explain the blended appearance of the hybrid offspring?_________incomplete dominance_________
32b) If two green frogs are crossed, what is the probability their offspring will be blue? green? yellow?
(perform a Punnett Square to solve) blue:__25%___green:___50%____yellow:____25%___
Y
B
Y
YY
YB
B
YB
BB
(YY=yellow, YB=green, BB=blue)
Use the Punnett Squares above to answer the questions below.
33.Which trait—white flowers or purple flowers—is controlled by a dominant allele? __white_____
34.In which generation (F1 or F2) are the parents hybrids? ___________F2_______________
35.In the F1 generation, what is the genotype of the offspring?______heterozygous (hybrid) Ww____
36.In the F2 generation, what percent of the offspring have purple flowers? _______25%__________